Vector control was once advocated as the primary tool to control lymphatic filariasis (LF), but with the discovery of the dramatic microfilaricidal activity of single dose treatment with diethylcarbamazine (DEC) alone, DEC plus ivermectin, DEC plus albendazole, or ivermectin plus albendazole there was a shift in emphasis to control strategies that relied on mass drug administration (MDA) alone. Interventions against the mosquito vector are however particularly attractive for bancroftian filariasis because the parasite does not multiply in the mosquito vector and in the case of anopheline mosquitoes, the efficiency with which ingested microfilariae develop into infective third stage larvae (L3) is poor relative to other mosquitoes. There are also important practical advantages to vector control, such as integration into MDA efforts into public health interventions against malaria and the distribution of insecticide impregnated mosquito nets (ITN) supported by the Global Fund. The long-term goal of this project is to determine the impact of combining MDA with ITN on the transmission of bancroftian filariasis in Papua New Guinea. The specific aims are: 1. To determine species composition, ecology and vectorial status of the principle filariasis vectors, the Anopheles punctulatus group of mosquitoes. This aim will test the hypothesis that not all members of the group are involved in transmission in Papua New Guinea. 2. To assess the impact of MDA alone and in combination with ITN on Annual Transmission Potential (ATP) in both high and moderate transmission areas. 3. To examine the role of Culex mosquitoes in transmission of filariasis in Papua New Guinea.